We do not have an unlimited budget, remember. We have already spent close to 70 Mn or so. Any two of Fernandes and Longstaff/Tielemans would likely cost about 90 Mn. And then we have a CB also to fill, who, if we look at the available good ones, won't be anything short of 60 Mn (Dias, and he is the cheapest). That alone takes spending beyond 200 Mn, into the 230 Mn range. And yes, I know it is structured payments over the course of years, but it still doesn't make it cheap.
On top of that, a striker is just too much, especially with no transfer fee for two years. I'm quite happy keeping Lukaku, thanks, rather than agreeing to the loan fee. Inter need to sell before buying, that's their headache to sort. We should be under very little pressure to sell.
Besides, it's still rumours, and we don't know the actual finances of the proposed deal. My opinion is that we should reject it. Anyhow, we can drop this topic until more news, I guess.
Also, just saying, it was Mourinho that converted Lukaku into a more static, target-man striker. Before that (and honestly, for Belgium) he was quite agile and running in channels behind defenders with good movement. Although his first touch was always okay-ish at best. That Lukaku can still be a decent fit for Ole, mind.